Surfing requires a high and large wave having a long cycle, i.e., a wave suitable for surfing. In order that such a wave suitable for surfing is produced on a shore, the shore should in general satisfy the following two conditions. One is that the topography of the sea bottom should have a proper slope to gradually increase the wave height toward the shore. The other is that swelling waves come surging relatively frequently toward the shore.
In spite of the sea surrounding Japan, only a few shores satisfy the two conditions as mentioned above, and many of the shores in Japan do not permit easy production of waves suitable for surfing, thus providing only a few chances for surf riders.
Even on a shore permitting surfing, on the other hand, a considerable change in weather or sea conditions may prevent production of a wave suitable for surfing. As a result, a surfing competition is often prevented from being held as planned.
Under such circumstances, there is a demand for an artificial-wave surfing shore where a wave suitable for surfing is constantly made available through artificial production.
However, there is not known at present an apparatus for producing an artificial wave, which permits production of a large artificial wave sufficient to allow surfing. The known trials to artificially produce a large wave include a method comprising placing concrete blocks or natural stones on the sea bottom to provide an appropriate slope on the sea bottom and thus producing a large wave by increasing the wave height, and another method comprising installing a smoothly convex structure on the sea bottom to deform a wave into a larger one, these constituting only examples in this area of research.
Under these circumstances, there is a demand for the development of an apparatus for producing an artificial wave, which permits artificial production of a wave suitable for surfing and the like on a shore, but such an apparatus for producing an artificial wave has not as yet been proposed.